The background description provided herein is for the purpose of generally presenting the context of the present invention. The subject matter discussed in the background of the invention section should not be assumed to be prior art merely as a result of its mention in the background of the invention section. Similarly, a problem mentioned in the background of the invention section or associated with the subject matter of the background of the invention section should not be assumed to have been previously recognized in the prior art. The subject matter in the background of the invention section merely represents different approaches, which in and of themselves may also be inventions. Work of the presently named inventors, to the extent it is described in the background of the invention section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention.
Electric lifting columns are widely applied to the fields such as home finishing, medical treatment and the like. A tube body of an existing electric lifting column generally includes an inner tube, a middle tube, and an outer tube which are successively sheathed from inside to outside, a housing fixedly connected with the upper end of the inner tube, a driving device arranged in the housing and a transmission assembly coupled with the driving device. In order to maximize a stroke of the electric lifting column, the transmission assembly generally includes a stage screw and a hollow screw with inner and outer threaded surface, which are assembled together so that the stage screw is screw-threaded into the hollow screw. Moreover, the inner tube and the middle tube are respectively provided with a transmission nut to be matched with the stage screw and the hollow screw, so that the relative extension of the inner tube, the middle tube and the outer tube is realized.
The transmission assembly may transfer the force onto the inner tube and the middle tube, thus causing extrusion among the inner tube, the middle tube and the outer tube, leading to transmission instability of the electric lifting column, and more seriously shortening the service life of the electric lifting column, in the case of non-uniform stress on the electric lifting column.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.